1. Technical Field
The present invention relates to a method and a system for improving a change of fuel in a bi-fuel vehicle, and more particularly, to a technology of greatly increasing a driving distance of a vehicle using LPG fuel and enabling a vehicle to be driven using LPG fuel by measuring a fuel pressure even when a level sensor measuring an LPG level in an LPG fuel tank is out of order.
2. Description of the Related Art
Generally, a bi-fuel vehicle represents a vehicle which uses different kinds of fuel such as gasoline/diesel-liquefied petroleum gas (LPG)/compressed natural gas (CNG) to generate power.
The bi-fuel vehicle essentially requires a system which may use all of the different kinds of fuel. For example, a vehicle using a combination of gasoline-LPG needs to include both of a gasoline fuel system for supplying general gasoline fuel to an engine and an LPG fuel system such as a vaporizer, a mixer, an LPG fuel tank (Bombe), and the like which are required to use LPG fuel.
Meanwhile, the bi-fuel vehicle using the gasoline-LPG M fuel may perform both of a manual change of fuel by driver's will and an automatic change of fuel at the time of a lack of fuel.
However, since a driver prefers to use cheaper LPG fuel than gasoline, he/she expects to completely consume the LPG fuel until the LPG fuel is under a measurable range.
However, the driver may not use LPG fuel at his/her desire level. Generally, an engine controller which is equipped in a vehicle permits the use of LPG fuel only within a range which may be measured by the level sensor in the LPG fuel tank in consideration of a safety problem of engine stalling while driving and performs a change of fuel to gasoline when the measured level of LPG fuel reaches a slight tolerance within the measurable range.
Therefore, an object of the present invention is to provide a method and a system for improving a change of fuel in a bi-fuel vehicle capable of increasing a distance which may be actually stably driven by only LPG fuel than that of the related art by measuring an LPG rail pressure and a pressure in an LPG fuel tank in addition to a level sensor in an LPG fuel tank and maximally using cheap LPG fuel by driving a vehicle using mixed fuel of gasoline and LPG in consideration of an actual injection quantity of LPG fuel and a mileage when it is determined that it is difficult to drive a vehicle using only the LPG fuel.
The contents described as the related art have been provided only for assisting in the understanding for the background of the present invention and should not be considered as corresponding to the related art known to those skilled in the art.